There is a medical diagnostic imaging apparatus that takes an image of a slice at a desired position and inclination in three-dimensional space, so as to use the image for diagnosis. In particular, a magnetic resonance imaging (hereinafter, referred to as MRI) apparatus is a medical diagnostic imaging apparatus, which mainly uses a nuclear magnetic resonance phenomenon of a proton, and it has no restriction on an imaging site, allowing any slice to be imaged non-invasively.
In general, a slice gradient magnetic field is applied to a subject placed in a static magnetic field, and simultaneously, a radio frequency magnetic field having a specific frequency is applied, thereby exciting nuclear magnetization within the slice that is targeted for imaging. Next, the nuclear magnetization excited by applying a phase encoding gradient magnetic field and a readout gradient magnetic field is provided with planar positional information, and a nuclear magnetic resonance signal generated by the nuclear magnetization is measured. Measurement of the nuclear magnetic resonance signal is performed repeatedly until filling up the measurement space referred to as k-space. The signals filled in the k-space are transformed to an image according to an inverse Fourier transform. Controlling gradient coils in three systems respectively associated with orthogonal triaxial directions allows the gradient direction of the magnetic field of each gradient magnetic field to be set in any direction in the three-dimensional space. In the MRI apparatus, spacial control of this gradient magnetic field implements imaging of any slice.
In the medical diagnostic imaging apparatus such as the MRI apparatus that is capable of taking an image of any slice, it is necessary to set an imaging slice of the diagnostic image and the position thereof at the time of examination. Generally, in the examination using the MRI apparatus, an imaging referred to as scout imaging is executed for setting the imaging position, and an imaging slice of the diagnostic image and the position thereof (imaging slice position) are set on the scout image being acquired.
A standard of the imaging slice position is established depending on an imaging target site and disease, and it is set assuming an anatomical organizational structure on the scout image as a landmark. In general, an imaging range displayed on the scout image is manually operated via a user interface, thereby setting the imaging slice position. Setting of the imaging slice position depends on the posture upon placing the subject and an individual difference of the anatomical organizational structure, and therefore it is necessary to configure the settings, every time taking an image of a new subject.
There is suggested a method for setting the imaging slice position automatically, in order to enhance the operability upon setting the imaging slice position. As a method of the automatic setting, for example, there is a technique to register in advance several types of diagnostic planes for deciding the imaging slice position automatically, together with a decision algorithm thereof, allowing user's selection (e.g., see Patent Document 1). In addition, there is a technique for storing an imaging range as a standard protocol, the range being set on a typical image (standard image), and adjusting the range so as to fit for individual subject (e.g., see Patent Document 2). On this occasion, the adjustment is performed according to mapping, by utilizing a transform matrix. Furthermore, there is a technique to perform the automatic setting by the use of image recognition (e.g., see Non Patent Document 1). It is expected that the automatization may produce effects such as not only operability enhancement, but also enhancement of imaging slice reproducibility at the time of follow-up examination.